It would be a stretch to say that Troy's Rensselaer Iron Works was the Los Alamos of its day. But the cluster of dark red brick buildings on the Hudson helped revolutionize naval warfare. With so much history within its walls, the Works deserved a far kinder fate than slow-motion immolation.

The original foundry on the Rensselaer Works site opened in 1846. In 1861 company president John Griswold and fellow industrialist John Winslow persuaded President Lincoln to build the first true ironclad warship, John Erickson's Monitor. Winslow's firm rolled the Monitor's plates in a mill south of the Rensselaer Works. Griswold's works forged her rivets and the bar iron of her pilot house. These components were shipped to Brooklyn, where the Monitor was assembled in an astounding 100 days.

Griswold died young in 1872, but the Rensselaer Works endured, rolling miles of rail that carried trains all over the United States. By the close of the 19th century, most of Troy's iron industry had moved west and the Rensselaer Works complex was sold to the Ludlow Valve Company, a leading manufacturer of fire hydrants.

The Ludlow Company ended its Troy operation in 1968-69. In October 1969, just a few months after being documented by the Historic American Engineering Survey, the vacant Rensselaer Rolling Mill (above) was set ablaze by an arsonist. After the fire, the gutted ruins of the pre-Civil War mill (left) resembled some Mathew Brady photograph of the shelling of Richmond.

The rolling mill was survived by a half-dozen later 19th century buildings. The oldest, a one-and-a-half story brick and timber-framed building with a patchwork quilt roof of multi-colored slates and asphalt (left above), was a link to the building of the Monitor. The largest was the adjoining 50,000 square foot two-and-a-half-story brick and steel truss "Merchant Mill" (right above) built in 1877-78.

Scolite Roofing, which succeeded the Ludlow Valve Company as the Works' tenant, closed in the late 1990s. After the City of Troy acquired the complex in 2001, it remained vacant except for a few sub-tenants. Most buildings were standing open to all comers and appeared to be being "demolished by neglect", when I was invited to tour the complex in July 2003. Disappointingly, the tour day was rainy, but this was not an opportunity to pass up in a monsoon.

We entered the former "Merchant Mill" through its Madison Street vehicle entrance (above). Inside, logs were being split under a spiderweb of hanging lights and a huge tarp that stretched off into the gloom. Threading our way through a Russian winter's supply of stacked firewood, we found our way into the quiet, looming dusk of the mill's main gallery (below).

Here the darkness was so dense and enveloping that I felt claustrophobic even in this cavernous space. Filtered through the plastic window covers, daylight was a greenish glow which dissipated into faint light-mist long before it could fall to the floor. Small holes in the roof and walls glimmered like faraway stars, and we could hear the echoes of rainwater streams splattering on concrete. Firing camera flashes to light our way, we found our path booby-trapped with junk.

It was predictable that free storage space would be filled with derelict boats and a ghost fleet of 1980s cars with lichen-like coverings of encrusted pigeon guano. But among the orphaned tires and hulks of scavenged appliances were mad magpies' nests of tangled cable, coolers stuffed with empty soda bottles, splintered pallets, buckled folding chairs, and everything in between, including a giant albino worm that the flash thankfully revealed to be coiled plastic tubing, and a Sequoia-sized plastic Christmas tree with hundreds of feet of tiny lights. The gutted shell of a 1960 Edsel hardtop sat with its nose almost buried in a sawdust dune. After failing to outflank it, we mounted a frontal assault on the soggy mound, while trying not to think of what might be burrowing beneath its surface.

After scaling the dune, we entered the single-story west wing, where dazzling light streamed through sections of roof collapsed by a blizzard. Here creepers had sent exploratory tendrils so deep into the gloom that their end-leaves were jaundiced yellow-white, with just the faintest tinge of green.

Because this wing had only person-scale doors, it was not filled with forgotten cars and truckloads of dumped trash. We found plenty of industrial debris, but shafts of daylight also illuminated ancient manufacturing artifacts.

In one corner, we discovered an enormous pulley from the belt and shaft system that once powered machinery, still mounted in the mill's iron pillar and truss frame (below).

Our circuitous wanderings had left us disoriented, so we were mildly surprised to step through an arched doorway and find ourselves in the Monitor-era west building (above). Here clerestory window openings and pried-off plastic window panels turned midnight into evening. We weren't sure of the building's original purpose, but, we could see a very large subterranean tank through holes in the buckled plank floor (below).

In this gallery we found numerous artifacts from the Ludlow Valve Company days. In excrutiating heat, a moulder, who had cultivated his skills during a four to seven year apprenticeship, would have tamped wet sand or earth into these custom-made wooden patterns and then painstakingly removed them to create a mould. A "puddler" would then have poured molten iron into the mould to cast a fire hydrant valve.

Avoiding the planks over the pit, we walked north through a one story passage to the forge, a later 19th century building with a corbeled cornice, twin cupola smokestacks, and another damaged roof (above). Near the hearth, we found a bin still filled with limestone, which would have been shoveled into the furnace with coal to achieve the correct combustion temperature, as well as a mechanical bellows and self-stoker (below). Abandoned equipment included a small crucible and a chain which seemed in scale with some monumental bicycle sprocket (bottom).

Even in 2003, there had years of talk about incorporating some of the Rensselaer Works buildings in an upscale riverside development. However, the only commercial activity we saw besides the woodsplitting operation was a crane loading scrap metal, including a Victorian sheet metal cornice, onto a barge.

In January 2005, the Civil War era west building was destroyed by an arsonist (below). Later that year, the city commissioned a strategic plan which suggested integrating the Works' nineteenth century buildings as commercial or museum space in an "Upper Hudson River & Estuaries Satellite Center" mixed use development. The plan noted that, unlike one smaller 19th century building that had collapsed from neglect, the Merchant Mill remained in good structural condition, except for the roof on its single story wing.

In late April 2008, Governor David Paterson came to the Rensselaer Works to announce that it would become the home of an ecological center, to include the monitoring hub of a $200 million sensor network covering 315 miles of the Hudson River.

The center would incorporate a restored Merchant Mill and other early buildings, as well as a municipal campus with bike paths, picnic grounds and docks. As the Albany Times-Union wrote," the future for the Rensselaer Iron Works seemed secure".

But in the late afternoon of May 25, 2008, the arsonists finally hit the trifecta. A blaze that drew firefighters from Troy, Albany, and Watervliet burned through the forge and a section at the rear of the Merchant Mill. Firefighters were unable to fight the fire from inside because of fears that the main gallery's bridge crane would collapse.

Many Trojans believed that much of the Merchant Mill could be saved (left). However, although the 125 year old iron trusses resisted strenuously (below left), the entire building was demolished within days.

Today, the Rensselaer Iron Works is survived chiefly by its machinery. Ironically, this includes the bridge crane (bottom), which may be re-erected as an outdoor display. It is scant consolation that the surviving small buildings will be combined with new structures in the Hudson River monitoring center project.